Variable resistor of sliding type

ABSTRACT

A variable resistor of sliding type with switch means incorporated therein, which comprises a resistance element and a conductive element mounted on a dielectric base in parallel relation, a slider having a contactor which slides on the resistance element and the conductive element, and switch means adapted to break the electrical connection of the resistance element with an external circuit when the slider is close to either end of the dielectric base.

United States Patent June 27, 1969, Japan, No. 44/62367; July 9, 1969, Japan, No. 44/66839; July 9, 1969, Japan, No. 44/66840; Aug. 8, 1969, Japan, No. 44/76 118 [54] VARIABLE RESISTOR OF SLIDING TYPE Primary Examinerbewis H. Myers Assistant ExaminerD. A. Tone Attorney-Stevens, Davis, Miller and Mosher ABSTRACT: A variable resistor of sliding type with switch means incorporated therein, which comprises a resistance element and a conductive element mounted on a dielectric base in parallel relation, a slider having a eonta'ctor which slides on 6 i 17 D i i the resistance element and the conductive element, and switch means adapted to break the electrical connection of the re- [52] U.S.Cl 338/178, Sistance element with an external circuit when the slider is 33 79 338/200 close to either end of the dielectric base.

PATENTEUJAN 41972 SHEET 0F 5 FIG.

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The present invention relates to a variable resistor of sliding type in which switch means are incorporated by a simple construction.

' Conventional variable resistor of sliding type are not provided with switch means in themselves. Therefore, it has been necessary to provide a microswitch or the likeseparately from the variable resistor, to effect a switching operation and much inconvenience has been encountered'in the preparation and operation of this equipments.

The present invention contemplates the provision of a variable resistor of sliding typ'ein which switch means is incorporated by a simple constritction. Namely, the variable resistor of sliding type according tothe present invention is so constructed that a resistance element and a conductive element are provided on a dielectric base in parallel relation and a slider having a contactor is moved in sliding contact with the resistance element ahd the conductive element, whereby electric resistance of a desired value, as determined by the position of the contactor in contact withfthe resistance element, is afforded to an associated extemal circuit, but when the slider is in a position close to either end of the dielectric base, the electrical contact of the slider with the resistance element or the conductive element is severed by switch means. Therefore, as compared with the prior art variable resistor of sliding type which requires a separate microswitch or the, like to effect a switching operation, the one according to the present invention is compact in construction by reason of the fact that the switch means is incorporated therein. In addition, the construction is so simple that the variable resistor can be assembled easily andiproduced very easily at low cost, and furthermore a stable circuit breaking operation can be I obtained. Thus, the present invention is of great practical advantage.

The present invention willbe described in detail hereinafter with reference tothe accompanying drawings, in which:

FIG. 1 is a longitudinal cross-sectional view of a first embodiment of the variable resistor of sliding type according to the invention;

FIG. 2 is a transverse cross-sectional view of the variable resistor shown in FIG. 1;

FIGS. 3 and 4 are fragmentary cross-sectional views illustrating the operation of the'variable resistor;

FIG. 5 is an electric circuit diagram of the variable resistor;

FIG.'6 is a transverse cross-sectional view of a second embodiment of variable resistor of sliding type of the invention;

FIG. 7 is a plan view of the dielectric base which is a component part of the variable resistor of FIG. 6;

FIG. 8 is an electric circuit diagram of the variable resistor of FIG. 6;

FIG. 9 is a transverse cross-sectional view of a third embodiment of the variable resistor of sliding type of the invention;

FIG. 10 is a plan view of the dielectric base of the variable resistor shown in FIG. 9;

FIG. 11 is an electric circuit diagram of the variable resistor of FIG. 9;

FIG. 12 is a side view, partially in section, of a fourth embodiment of the variable resistor of sliding type according to the invention;

FIG. 13 is a plan view of the dielectric base of the variable resistor shown in FIG. 12;

FIG. 14 is an electric circuit diagram of the variable resistor shown in FIG. 12;

FIG. 15 is a side view, partially in section, of a fifth embodiment of the variable resistor of sliding type according to the invention;

FIG. 16 is a plan view of the dielectric base of the variable resistor shown in FIG. 15 and FIG. 17 is an electric circuit diagram of the variable resistor ofFIG. 1s.

,2 EMBOIJIMENT 1 vided on the dielectric base 'l at a location adjacent one end of the resistance 4 and slightly spaced above said resistance element. The switching element 8 is electrically isolated also from the conductive element 5 andan erid portion thereof is extended to the outside of the dielectric base 1 to constitute a terminal 9. i ii i i i The upper surface of the dielectric base I is covered by a box-shaped housing llhaving'a slot lo formed in the top wall thereof, and a slider 16 is withinthe space defined by said box-shaped housing 11 and 'the dielect ric base I. The slider 16 has a contactor l4 fixed tothe underside thereof,

which consists of a resilient metallic striphavingcontact legs 12, 13 connected thereto for sliding engagement with the resistance element 4 andthe conductive element 5 respectively, and has a leaf spring 15 tittedgtothe upper surface thereof to be urged downwardlythereby. The arrangement is made such that when the slider 16 is located onjthatsideof the dielectric base 1 where the switching element 8 is provided, the contact leg 12 of the contactor l4 isdisengaged fromthe resistance element 4 and brought into contactwjith the switching element 8. The slider 16 is provided at the center of t the upper st rface thereof with an operating means 17 extends outwardly through the slot 10 of the box-shaped housing 11.;By operating the operating means 17,.the slider is moved by being guided by the elongate projections 2,3, with the contact legs 12, 13 of the contactor l4sliding on,the resistance element 4 and the conductive element 5 in contact therewith respectivey The variable resistor of sliding type constructed as described above operates inthe follbwing mannerz First of all, when the contact leg 12 of the contactor fixedto the slider 16 is located on the resistance element fl as indicated by the solid line in FIG. 5, a value of resistance can be obtained across the terminals 6, 6 and the terminals 7, 7', as in the case of ordinary variable resistor of sliding As the slider 16 is further moved by the operating means 17 toward that end of the dielectric base where the switching element 8 isprovided and is located in the position shown in FIG. 3, th e contact leg 12 of contactor l4 contactsthe,resistanceelernent 4 and the switching element 8. Asthe slider 16 is moved still further from the position shown inFIG. 3, the contact leg,12 of the contactor l4 rises on the switching element 8 as shown in FIG. 4. In this case, the contact ieg I2 is located in the position indicated by the dotted line in FIG. 5 and a value of resistance cannot be obtained, because the switchingelementll and the conductive element 5 are electrically shtirted, through the contactor 14 and hence the terminals 7, 7' the terminals 6, 6' are electrically shorted. In otherwords, the switch mechanism has been actuated. a i i Although the foregoing description has been given with reference to the housing wherein the variable resistor comprises one set of the resistance element 4 and the conductive element 5, it will be obvious thatthe variable resistor may comprise two or more sets of the resistance element and the conductive element, and in this casethe number of the switch mechanism increases accordingly.

EMBODIMENT 2 Referring to FIGS. 6-8, reference n rrneral 101 .designates a mounting baseplate made of an insulating material and having elongate projections 102, 103 formed along the opposite side edges thereof to provide guides. on, the dielectricbase 101 are provided a resistance layer 104 and a conductive element 105 in parallel relation. The resistance layer 104 is provided with terminal connecting members 106, 107 at the opposite ends thereof. An extension 109 of the conductive element is provided at one end of the conductive element 105 with an electrical connection breaking space 108 therebetween. Reference numerals 110 and 111 designate terminals extending outwardly of the dielectric base 101 from the terminal connecting members 106, 107 respectively. Reference numerals 112 and 113 designate terminals extending outwardly of the dielectric base 101 from the opposite ends of the conductive element 105. Reference numerals 114 and 115 designate terminals extending outwardly of the dielectric base 101 from the opposite ends of the extension 109 of the conductive element respectively.

The dielectric base 101 is covered by a box-shaped housing 117 which has a slot 116 formed in the top wall thereof and a slider 120 is disposed with the space defined by said boxshaped housing 117 and said dielectric base 101. The slider 120 has a contactor 118 fixed to the underside thereof, which consists of a resilient metallic member to slide on the resistance layer 104, the terminal connecting members 106, 107, the conductive element 105 and the extension 109 of said conductive element. On the upper surface of the slider 120 is provided a leaf spring 119 to urge said slider downwardly. An operating means 121 is connected to the center of the upper surface of the slider 120, extending outwardly of the boxshaped housing 117 through the slot 116. By operating the operating means 121, the slider 120 is moved in sliding contact with the resistance layer 104, the terminal connecting members 106, 107, the conductive element 105 and the extension 109 of said conductive element, while being guided by the elongate projections 102, 103. Reference numeral 122 designates a sliding plate provided on the inside surface of the top wall of the box-shaped housing 117, against which the leaf spring 119 bears during sliding movement of the slider 120.

The operation of the variable resistor of sliding type constructed as described above will be explained in detail hereunder: First of all, when the contactor 118 fixed to the slider 120 is in the position indicated by the solid line in FIG. 8, a value of resistance can be obtained across the terminals 110, 111 and the terminals 112, 113, as in the case of ordinary variable resistor. However, when the slider 120 is moved by the operating means 121 and the contactor 1 18 is brought to a position on the extension 109 of the conductive element as indicated by the dotted line in FIG. 8, past the electrical connection breaking space 108, a value of resistance cannot be obtained because the terminal connecting member 107 and the extension 109 of the conductive element are electrically conducted through the contactor 118 and hence the terminal 111 and tenninals 114, 115 are electrically shorted. In other words, the switch mechanism has been actuated.

Although the foregoing description has been given only on the case when the variable resistor incorporates one switch mechanism, it is to be understood that by providing the electrical connection breaking space 108 at two or more locations, the same number of switch mechanism can be obtained. It is also to be understood that the resistance layer 104 and the conductive element 105 may be provided in two or more sets and, in this case also, the switch mechanism can be provided in a desired number as in the preceding embodiment.

EMBODIMENT 3 Referring to FIGS. 9-11, reference numeral 201 designates a mounting baseplate made of an insulating material and having elongate projections 202, 203 formed along the opposite side edges thereof to provide guides. A resistance mounting plate 202 and a conductive element 205 are provided on the dielectric base 201 in parallel relation, and terminal connecting members 206, 207 are provided at the opposite ends of said resistance mounting plate 204. On the resistance mounting plate'204 is provided a resistance layer 208 which has one end electrically connected to the terminal connecting member 206, with the other end connected to a terminal connecting member 210 which defines an electrical connection breaking space 209 between it and the other terminal connecting member 207. Reference numerals 211, 212 and 213 designate terminals extending outwardly through the dielectric base 201 from the terminal connecting members 206, 207 and 210 respectively. Reference numerals 214 and 215 (through numeral 214 is not depicted in the drawing) designate terminals extending outwardly through the dielectric base 201 from the opposite ends of the conductive element 205.

The dielectric base 201 is covered by a box-shaped housing 217 which has a slot 216 formed in the top wall thereof, and a slider 220 is disposed within the space defined by said boxshaped housing 217 and said dielectric base 201. The slider 220 has a contactor 218 fixed to the underside thereof, which consists of a resilient metallic member to slide on the resistance layer 208 on the resistance layer mounting plate 204, the terminals 206, 207 and 210, and the conductive element 205. On the upper surface of the slider 220 is provided a leaf spring 219 to urge said slider downwardly. An operating means 221 is connected to the center of the upper surface of the slider 220, extending outwardly of the box-shaped housing 217 through the slot 216. By operating the operating means 221, the slider 220 is moved in sliding contact with the resistance layer 208, the terminals 206, 207, 210 and the conductive element 205, while being guided by the elongate projections 202, 203. Reference numeral 222 designates a covering plate provided on the inside surface of the top wall of the box-shaped housing 217, against which the leaf spring 219 bears during sliding movement of the slider 220.

The variable resistor of sliding type of the construction described above operates as follows: First of all, when the contactor 218 fixed to the slider 220 is located on the resistance layer 208 formed on the resistance mounting plate 204, as indicated by the solid line in FIG. 11, a value of resistance can be obtained across the terminals 211, 213 and the terminals 214, 215, as in the case of ordinary variable resistor. However, when the slider 220 is moved by the operating means 221 and the contactor 218 is shifted onto the terminal connecting member 207, as indicated by the dotted line in FIG. 11, pas the terminal connecting member 210 and the electrical connection breaking space 209, a value of resistance cannot be obtained because of the terminal connecting member 207 and the conductive element 205 are electrically conducted through the contactor 218 and hence the terminal 212 and the terminals 214, 215 are electrically shorted. In other words, the switch mechanism has been actuated.

Although the foregoing description has been given only on the case when the resistance layer 208 and the terminal connecting members 206, 207, 210 are provide on the resistance mounting plate 204, it is to be understood that the resistance layer 208 and the terminal connecting members may be provided directly on the dielectric base 201. Further, although in the embodiment described above, one switch mechanism is incorporated in the variable resistor, the number of the switch mechanism can be increased by providing the electrical connection breaking space 209 at two or more location. as by dividing the resistance layer 208. It is also to be understood that the resistance layer 208 and the conductive element 205 may be provided in two or more sets and, in this case also, the number of the switch mechanism can optionally be deter mined as in the preceding embodiments.

EMBODIMENT 4 Referring to FIGS. 12-14, reference numeral 301 designates a mounting baseplate made of an insulating material and having elongate projections 302, 303 formed along the opposite side edges thereof to provide guides. A resistance element 304 and a conductive element 305 are provided on the dielectric base 301 in parallel relation and terminal connecting members 306, 307 are provided at the opposite ends of said resistance element 304. The surface of the terminal connecting member 306 is partially coated with an electric insulation layer 308 and a switch contact arm 309 is provided adjacent that end of the conductive element 305 which is closer to said insulation layer 308. Reference numerals 310 and 311 designate terminals extending outwardly through the dielectric base 301 from the terminal connecting members 306, 307 respectively, and reference numerals 312 and 313 designate terminals extending outwardly through the dielectric base 301 from the opposite ends of the conductive element 305. Reference numeral 314 designates a terminal extending outwardly through the dielectric element 301 and connected to the switch contact am 309.

The dielectric element 301 is covered by a box-shaped housing 316 which has a slot 315 formed in the top wall thereof, and a slider 319 is disposed within the space defined by said box-shaped housing 316 and said dielectric base 301. The slider 319 has a contactor 317 fixed to the underside thereof, which consists of a resilient metallic member to slide on the resistance element 304, the terminal connecting members 306, 307 and the conductive element 305. On the upper surface of the slider 319 is provided a leaf spring 318 to urge said slider downwardly. The contactor 317 is arranged to contact the switch contact arm ata portion thereof. An operating means 320 is connected to the center of the upper surface of the slider 319, extending outwardly of the box-shaped housing 316 through the slot 315. By operating the handle mounting arm 320, the slider 319 is moved, with the contactor 317 in sliding contact with the resistance element 304, the terminals 306, 307 and the conductive element 305, by being guided by the elongate projections 302, 303 of the dielectric base 301. Reference numeral 321 designates a covering plate provided on the inside surface of the top wall of the box-shaped housing 316, against which the leaf spring 318 bears during sliding movement of the slider 319. The covering plate 321 is provided with a recess at a portion of that end thereof which is closer to the switch contact arm 309, for interlocking engagement with a projection (not shown) formed on the leaf spring 318 when the contactor 317 is brought into contact with the switch contact arm 309.

The variable resistor of sliding type constructed as described above operates in the following manner: First of all, when the contactor 317 fixed to the slider is in engagement with the resistance element 304 as indicated by the solid line in FIG. 14, a value of resistance can be obtained across the terminals 310, 311 and the terminals 312, 313, as in the case of ordinary variable resistor. However, when the slider 319 is moved by the operating means 320 and the contactor 317 is located on the electric insulation layer 308 formed on the terminal connecting member 306, the contactor 317 contacts the switch contact member 309 at a portion thereof and a value of resistance cannot be obtained as indicated by the dotted line in FIG. 14. In this case, the switch contact member 309 and the conductive element 305 are electrically conducted through the conductor 317, and the terminals 312, 313 and the terminal 314 are electrically shorted. Namely, the switch mechanism has been actuated.

Although one switch mechanism is provided in the variable resistor, two switch mechanisms can be obtained by providing another set of electric insulation layer and switch contact member on the side of the resistance element 304 and the conductive element 305 opposite to the electric insulation layer 308 and the switch contact member 309. Further, the resistance element 304 and the conductive element 305 may be provided in two or more sets, and in this case also, the number of the switch mechanism can optionally be determined. It is also to be understood that the switch contact member may be provided adjacent the terminal connecting member.

EMBODIMENT 5 Referring to FIGS. -17, reference numeral 401 designates a mounting baseplate made of an insulating material and having elongate projections 402, 403 formed along the opposite side edges thereof to provide guides. A resistance element 404 and a conductive element 405 are provided on the dielectric base 401 in parallel relation, and terminal connecting members 406,407 are provided at the opposite ends of the resistance element 404. The surface of the terminal connecting member 406 is partially coated with an electric insulation layer 408 and a conducting member 409 is provided on the insulation layer 408, which is electricallyinsulated from the terminal connecting member 406. Reference numerals 410 and 411 designate terminals extending outwardly through the dielectric base 401 from the terminal connecting members 406, 407 respectively. Reference numerals 412 and 413 designate terminals extending outwardly through the dielectric base 401 from the opposite ends of the conductive element 405, and reference numeral 414 designates a terminal connected to the conducting member 409 and extending outwardly of the dielectric base 401.

The dielectric base 401 is covered by a box-shaped housing 416 which has a slot 415 formed in the top wall thereof. A slider 419 is disposed within the space defined by the boxshaped housing 416 and the dielectric base 401, which has fixed to the underside thereof a contactor 417 consisting of a resilient metallic member adapted to slide on the resistance element 404, the terminal connecting members 406, 407 and the conductive element 405. On the upper surface of the slider 419 is provided a leaf spring 418 to urge said contactor downwardly. An operating means 420 is connected to the center of the upper surface of the slider 419, extending outwardly of box-shaped housing 416 through the slot 415. By operating the operating means 420, the slider 419 is moved, with the contactor 417 being in sliding contact with the resistance element 404, the terminal connecting members 406, 407 and the conductive element 405, by being guided by the elongate projections 402, 403 of the dielectric base 401. Reference numeral 421 designates a covering plate provided on the inside surface of the top wall of the box-shaped housing 416, against which the leaf spring 418 bears during sliding movement of the slider 419. The covering plate 421 has a recess formed in its end closer to the conducting member 409, for interlocking engagement with a projection (not shown) formed on the leaf spring 418 when the contactor 417 is brought into contact with the conducting member 409 on the terminal connecting member 406.

Now, the operation of the variable resistor of sliding type having the above-described construction will be explained. First of all, when the contactor 417 fixed to the slider 419 is positioned on the resistance element 404 as indicated by the solid line in FIG. 17, a value of resistance can be obtained across the terminals 410, 411 and the terminals 412, 413 as in the case of ordinary variable resistors. However, when the slider 419 is moved by operating the operating means 420 and the contactor 417 is located on the conducting member 409 on the terminal connecting member 406, a value of resistance cannot be obtained as indicated by the dotted line in FIG. 17. In this case, the conducting member 409 and the conductive element 405 are electrically conducted through the contactor 417, and the terminals 412, 413 and the terminal 414 are electrically shorted. Namely, the switch mechanism has been actuated.

Although in the embodiment described above, the conducting member 409 is provided on the terminal connecting member 406 through the electrical insulation layer 408, it may be provided on the terminal connecting member 407 or at a suitable location on the resistance element 404. Further, although the variable resistor is provided with one switch mechanism, the number of the switch mechanism can 0ptionally be increased by providing the corresponding number of conducting member 409 on the resistance element 404 and the terminal connecting members 406, 407 as stated above. It is also to be understood that the resistance element 404 and the conductive element 405 may be provided in two or more sets and in this case also, the number of switch mechanism can be optionally determined.

What is claimed is:

l. A variable resistor of sliding type comprising a resistance element and a conductive element provided on a dielectric base in parallel relation,

a slider having contactor and caused to move on said base with said contactor in sliding contact with said resistance element and said conductive element,

switch means for breaking the electrical contact of said contactor of the slider with said resistance element or said conductive element when said slider is in a position adjacent either end of said dielectric base and thereby switching the electrical connection of said resistance element with an external circuit, and

a box-shaped housing covering and supporting said slider on said dielectric base.

2. A variable resistor of sliding type as defined in claim 1,

wherein said switch means includes a switch contact member which is provided on said dielectric base at a location adjacent one end of said resistance element and adapted to push said contactor upwardly when the contactor is brought into engagement therewith, thereby to break the electrical contact of said contactor with said resistance element.

3. A variable resistor of sliding type as defined in claim 1, wherein said resistance element consists of a resistance layer and said switch means includes at least one electrical connection breaking space provided in said conductive element.

4. A variable resistor for sliding type as defined in claim I, wherein said resistance element consists of one or a plurality of resistance layers and said switch means includes one or a plurality of electrical connection breaking spaces provided in said resistance layer.

5. A variable resistor of sliding type as defined in claim 1, wherein said switch means includes an electric insulation layer formed on a portion of said resistance element adjacent one end thereof and at least one switch contact member provided on said dielectric base.

6. A variable resistor of sliding type as defined in claim 1, wherein said switch means includes a conducting member provided on said resistance element at a location adjacent one end thereof, with an electric insulation layer intervening therebetween, for contact with said contactor. 

1. A variable resistor of sliding type comprising a resistance element and a conductive element provided on a dielectric base in parallel relation, a slider having contactor and caused to move on said base with said contactor in sliding contact with said resistance element and said conductive element, switch means for breaking the electrical contact of said contactor of the slider with said resistance element or said conductive element when said slider is in a position adjacent either end of said dielectric base and thereby switching the electrical connection of said resistance element with an external circuit, and a box-shaped housing covering and supporting said slider on said dielectric base.
 2. A variable resistor of sliding type as defined in claim 1, wherein said switch means includes a switch contact member which is provided on said dielectric base at a location adjacent one end of said resistance element and adapted to push said contactor upwardly when the contactor is brought into engagement therewith, thereby to break the electrical contact of said contactor with said resistance element.
 3. A variable resistor of sliding type as defined in claim 1, wherein said resistance element consists of a resistance layer and said switch means includes at least one electrical connection breaking space provided in said conductive element.
 4. A variable resistor for sliding type as defined in claim 1, wherein said resistance element consists of one or a plurality of resistance layers and said switch means includes one or a plurality of electrical connection breaking spaces provided in said resistance layer.
 5. A variable resistor of sliding type as defined in claim 1, wherein said switch means includes an electric insulation layer formed on a portion of said resistance element adjacent one end thereof and at least one switch contact member provided on said dielectric base.
 6. A variable resistor of sliding type as defined in claim 1, wherein said switch means includes a conducting member provided on said resistance element at a location adjacent one end thereof, with an electric insulation layer intervening therebetween, for contact with said contactor. 